Leicester City's Christian Fuchs, dejected after the match.
The interim boss, officially in charge only until the end of this season, said that the switch to a 3-4-1-2 system had been in his thoughts before the game.
Vardy got on the scoresheet to take his tally to nine goals in his last 13 matches in all competitions, but it was not enough to prevent Leicester going out after losing 2-1 on aggregate.
Atletico Madrid courageously managed to see out what their manager desribed as "complicated tie" but Simeone was left in awe of Leicester's fighting spirit.
The La Liga giants had to be on their game defensively to leave the King Power Stadium with the result needed to qualify for the semi-final of the Champions League. I've said we'd sit down at the end of the season.
"The momentum was with us after Jamie Vardy's goal and we needed that second goal when the opportunity came, but it just wasn't to be".
"They blocked a couple of efforts near the line that on another day might have gone in but it wasn't to be".
Against a defense as well-drilled and as compact as Atletico's, that was always going to be a bridge too far for Craig Shakespeare's side.
"What a great performance from our competitors tonight".
Atletico looked like they could pick Leicester off at will as they kept the ball and nearly killed the tie with Griezmann's exceptional work rate underpinning their performance.
Not even two minutes later the Foxes had yet another chance to double their lead, after a crucial Wes Morgan clearance on one end led the team on a blistering counter. After the break they were relentless, whacking Atletico around the head again and again as they tried to batter their way into the semi-final.
"We were living in fear all night about what they might achieve as they kept coming forwards".
Germany's goalkeeper Manuel Neuer is out for the rest of the season after fracturing his left foot in Bayern Munich's Champions League defeat at Real Madrid, his club announced Wednesday.
Having claimed a 1-0 first-leg victory courtesy of Antoine Griezmann's contentious penalty, Diego Simeone's side were generally efficient in Tuesday's return leg - Saul Niguez's first half header leaving Jamie Vardy's goal immaterial. We brought Leo [Leonardo Ulloa] on to cause an aerial threat and it started paying dividends for us.
"What they did superbly was getting lots of people down the flanks".
"It's hard to talk about that", Ulloa said when asked about Ranieri's exit. "We responded with a very good defensive work", Atletico chief coach Diego Simeone told his club's website.
"We're a squad that believes we can do things some people probably didn't think we're capable of, but we just keep pushing ourselves on the training field and out on the pitch". On the basis of that improbable and rapid climb, little will seem impossible for the years or generations to come at Leicester.
Leicester Citys Ben Chilwell vies for the ball with Atletico Madrids Fernando Torres (right) during the UEFA Champions League quarterfinal second leg at the King Power Stadium in Leicester, on Tuesday.